1. Field
The present disclosure relates to determining the location of an object from its speed and direction of travel. More particularly, the present disclosure relates to determining the position of a wheeled object from measurements of the wheel's orientation and rotation.
2. Description of the Related Art
It is often desirable to track the position of an object as it moves throughout a tracking area. A facility such as, for example, a retail store, a hospital, an airport, or a warehouse, may wish to monitor the location of objects such as vehicles, carts, carriers, transports, and the like. The facility can use object location information, for example, to track inventory movements, to improve access to and retrieval of the objects, to identify clustering, queuing, or traffic patterns, and/or to prevent misplacement, loss, or theft of the objects. In one example, a retail store may wish to track the position of shopping carts so as to prevent the carts from being removed or stolen from a bounded area, such as a parking lot, or to ensure that a shopping cart has passed through a checkout lane before exiting the store. In another example, a facility may wish to map the architectural configuration of a building by using a wheeled object to measure positions of various landmarks.
A variety of methods have been used to determine the position of an object in a tracking area. For example, a radio frequency (RF) transmitter or tag can be attached to the object, and one or more receivers in the tracking area can monitor tag transmissions to determine object position. However, such methods are disadvantageous if the tracking area is large, which requires installation of many receivers, or if the tracking area contains structures that attenuate the tag transmissions. Other methods utilize the Global Positioning System (GPS) to determine position. However, GPS methods can fail if the GPS signal is blocked or if the visibility of satellites is interrupted. Further, both GPS systems and RF tag and receiver systems can be expensive and difficult to implement.